Abstract
In this article we discuss the nuclear symmetry energy in the regime of hadronic degrees of freedom. The density dependence of the symmetry energy is important from very low densities in supernova explosions, to the structure of neutron-rich nuclei around saturation density, and to several times saturation density in neutron stars. Heavy ion collisions are the only means to study this density dependence in the laboratory, and transport theories are used to extract the symmetry energy. We finally discuss some examples, which relate particularly to the high density symmetry energy, which is of particular interest today. We point out the status and open problems in the theoretical analyses of HIC.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
C. Fuchs and H. H. Wolter, “Modelization of the EOS,” Eur. Phys. J. A 30, 5 (2006).
C. Xu and B. A. Li, “Forces in hadronic systems and effective interactions, symmetry energy, asymmetric matter, neutron matter,” Phys. Rev. C 81, 064612 (2010).
M. B. Tsang, J. R. Stone, F. Camera, P. Danielewicz, S. Gandolfi, K. Hebeler, C. J. Horowitz, J. Lee, W. G. Lynch, Z. Kohley, R. Lemmon, P. Möller, T. Murakami, S. Riordan, X. Roca-Maza, F. Sammarruca, A. W. Steiner, I. Vidaña, and S. J. Yennello, “Symmetry energy, asymmetric matter, neutron matter, equations of state of neutron-star matter, threenucleon forces,” Phys. Rev. C 86, 015803 (2012).
C. J. Horowitz, E. F. Brown, Y. Kim, W. G. Lynch, R. Michaels, A. Ono, J. Piekarewicz, M. B. Tsang, and H. H. Wolter, “A way forward in the study of the symmetry energy: experiment, theory, and observation,” J. Phvs. G 41, 093001 (2014).
A. W. Steiner, J. M. Lattimer, and E. F. Brown, “The neutron star mass-radius relation and the equation of state of dense matter,” Astrophys. Jour. Lett. 765, L5 (2013).
P. Chomaz, F. Gulminelli, W. Trautmann, and S. Yenello, “Dynamics and thermodynamics with nuclear degrees of freedom,” Eur. Phys. J. A 30 (1), (2006).
B. A. Li, A. Ramos, G. Verde, and I. Vidaña, “Topical issue on the nuclear symmetry energy,” Eur. Phys. J. A 50, 9 (2014).
V. Baran, M. Colonna, V. Greco, and M. Di Toro, “Reaction dynamics with exotic nuclei,” Phys. Rep. 410, 335 (2005).
B. A. Li, L. W. Chen, and C. M. Ko, “Recent progress and new challenges in isospin physics with heavy-ion reactions,” Phys. Rep. 464, 113 (2008).
J. B. Natowitz, G. Röpke, S. Typel, D. Blaschke, A. Bonasera, K. Hagel, T. Klähn, S. Kowalski, L. Qin, S. Shlomo, R. Wada, and H. H. Wolter, “Symmetry energy of dilute warm nuclear matter,” Phys. Rev. Lett. 104, 202501 (2010).
M. B. Tsang, Y. X. Zhang, P. Danielewicz, M. Famiano, Z. X. Li, W. G. Lynch, and A. W. Steiner, “Constraints on the density dependence of the symmetry energy,” Phys. Rev. Lett. 102, 122701 (2009).
G. Y. Shao, M. Di Toro, B. Liu, M. Colonna, V. Greco, Y. X. Liu, and S. Plumari, “Hadron-quark phase transition in asymmetric matter with dynamical quark masses,” Phys. Rev. D 83, 094033 (2011).
J. Rizzo, M. Colonna, and M. Di Toro, “Fast nucleon emission as a probe of the momentum dependence of the symmetry potential,” Phys. Rev. C 72, 064609 (2005).
V. Giordano, M. Colonna, M. Di Toro, V. Greco, and J. Rizzo, “Isospin emission and flow at high baryon density: A test of the symmetry potential,” Phys. Rev. 81, 064611 (2010).
H. H. Wolter, M. Zielinska-Pfabe, P. Decowski, M. Colonna, R. Bougault, and A. Chbihi, “Symmetry energy dependence of light fragment production in heavy ion collisions,” EPJ Web of Conf. 66, 03097 (2014).
Y. X. Zhang, M. B. Tsang, Z. X. Li, H. Liu, “Constraints on symmetry energy and nucleon effective mass splitting with heavy ion collisions,” arXiv:1402.3790 [nucl-th].
P. Russotto, M. D. Cozma, A. Le Fevre, Y. Leifels, R. Lemmon, Q. Li, J. Lukasic, and W. Trautmann, “Flow probe of symmetry energy in relativistic heavyion reactions,” Eur. Phys. J. A 50, 38 (2014).
G. Ferini, M. Colonna, T. Gaitanos, and M. Di Toro, “Aspects of particle production in isospin-asymmetric matter,” Nucl. Phys. A 762, 147 (2005).
Z. Xiao, B. A. Li, L. W. Chen, G. C. Yong, and M. Zhang, “Circumstantial evidence for a soft nuclear symmetry energy at supra-saturation densities,” Phys. Rev. Lett. 102, 062502 (2009)
V. Prassa, G. Ferini, T. Gaitanos, H. H. Wolter, G. Lalazissis, and M. Di Toro, “In-medium effects on particle production in heavy ion collisions,” Nucl. Phys. A 789, 311 (2007)
Z. Q. Feng and G. M. Jin, “Probing high-density behavior of symmetry energy from pion emission in heavy-ion collisions,” Phys. Lett. B 683, 146 (2010)
J. Hong and P. Danielewicz, “Subthreshold pion production within a transport description of central Au+Au collisions,” Phys. Rev. C 90, 024605 (2014).
W. Reisdorf, FOPI collaboration, “Systematics of pion emission in heavy ion collisions in the 1 AGeV regime,” Nucl. Phys. A 781, 459 (2007).
G. Ferini, T. Gaitanos, M. Colonna, M. Di Toro, and H. H. Wolter, “Isospin effects on sub-threshold kaon production at intermediate energies,” Phys. Rev. Lett. 97, 202301 (2006).
P. Danielewicz and J. Lee, “Symmetry energy II: Isobaric analog states,” Nucl. Phys. A 922, 1 (2014).
S. Typel, G. Röpke, T. Klähn, D. Blaschke, and H. H. Wolter, “Composition and thermodynamics of nuclear matter with light clusters,” Phys. Rev. C 81, 015803 (2010).
Author information
Authors and Affiliations
Corresponding author
Additional information
The article is published in the original.
Rights and permissions
About this article
Cite this article
Wolter, H.H. The nuclear symmetry energy in heavy ion collisions. Phys. Part. Nuclei 46, 781–785 (2015). https://doi.org/10.1134/S1063779615050305
Published:
Issue Date:
DOI: https://doi.org/10.1134/S1063779615050305